Extremely odd "B" blinker light behavior

[worzella]

On my '75 console, when I turn on the emergency flashers, they all blink on the outside of the car and the emergency switch flashes and the "B" blinker light also flashes. Das ist gut!

However, when I just turn on one of my blinkers (L or R), they blink just fine outside, but the "B" blinker light on the dash ONLY blips on for a second when I initially flick the blinker on.... i.e. - as they blink outside, this "B" light stays off on the dash.

Very odd.. anyone ever see this. The flasher unit is new, so I don't expect that would be the issue.

Thanks,

Randy

[adawil2002]

Check/replace fuses & clean the fuse box contacts.

Check/replace bulbs, one blink usually means a bulb is burned out

Check and clean grounds.

Check and clean bulb sockets.

Recommend searching the forum for similar posts on this topic there is a wealth of material on this one.

[Mike Self]

the problem is the small set of relay points inside the flasher box--they need a little tweaking to make 'em work properly again. If you can't find the post, drop me an e-mail and I'll send you instructions.

cheers

mike

[c.d.iesel]

..."the flasher unit is new, so

I don't expect that would be the issue?"

new as NEW from BMW ?

new as from a box of other 'new' old relays?

new as from NAPA or AutoZone ?

instrument cluster got good connections?

""..............." ......."......" ..... grounds?

[im3crazy]

WHen I've seen this it's been a failure of the blinker relay - IIRC the lead for the dash indicator is fed from the relay output in the blinker - see 31 in diagram attached and lead #8 which lights E on the dash pod. Failed components or incorrect flasher substitutes can also cause the blinker to continuously cycle.

BMW 2002 Electric Diagram.pdf

[worzella]

Thanks everyone.. the flasher relay is new BMW, either from Max, Blunt or Bav Auto... can't recall.

I am rebuilding everything, so yes, every connector has been ground to shiny metal and all fuses/grounds are A-OK.

I'll look up Mike's old post and see what I can find.

Randy

[worzella]

Mike, I think I found your post.. thanks

I'd suspect the flasher unit itself...it has two relays inside, one for

the outside lights and one for the dash blinker. I'll bet the relay points

for the inside blinker are stuck closed.

You can unclip the flasher unit from under the dash (smaller black box

near the hood release handle) and carefully pry off the cover (leave it

electrically connected). Turn on the turn signals and observe the two sets

of points. They should open and close opposite of each other in time with the lights flashing. If you see stuck points, turn off the signals and carefully clean the sticking points. Then try it. You might have to carefully bend the moveable contact so it won't stick again.

That may well cure the problem.

cheers

mike

[JohnS]

If the flasher relay checks out OK, you might want to make sure that your instrument cluster is properly grounded. My Blinker light in the instrument cluster used to not always flash correctly until I ran an extra ground wire to the cluster.

[ThatGuy]

I had an issue with my "B" blinker light on my gauges. It would seemingly only work when I had something in the trunk so I checked grounds, light sockets, wiring, bulbs etc.

Finally I traced it back to the actual circuit board in the gauge that wasn't making a good solid contact with the bulb socket. It still works sometimes and, coincidentally, usually right after I put stuff in the trunk.

If everything else checks out it may be that. I haven't fixed it yet because I have not gotten around to taking my gauge cluster apart, again.

[FL_Inka]

On my '75 console, when I turn on the emergency flashers, they all blink on the outside of the car and the emergency switch flashes and the "B" blinker light also flashes. Das ist gut!

However, when I just turn on one of my blinkers (L or R), they blink just fine outside, but the "B" blinker light on the dash ONLY blips on for a second when I initially flick the blinker on.... i.e. - as they blink outside, this "B" light stays off on the dash.

Very odd.. anyone ever see this. The flasher unit is new, so I don't expect that would be the issue.

Thanks,

Randy

I have this same exact problem! I've replaced the flasher relay with a new VW 3wire flasher, same problem. Actually, it works a little better now......

The electrical diagram from the Haynes manual does not show my particular car exactly ('74 2002 US model with the 12 Point Fuse box). But from what I gather based on the other schematics in the Haynes book, the flasher "B" signal to the dash works a little something like this:

The hazard switch gets its power from a point on the fuse box. From there, it runs over to the flasher relay. From the relay, ONE signal goes to the "B" light, terminal "C" on the flasher relay, and the outside signals get their power from terminal 49A on the flasher relay.

What I notice in troubleshooting is that when I turn on the hazard switch and measure the "C" signal at the relay, the signal is 12V on and off.

However, when I use my turn signal switch behind the steering wheel, left or right, the same "C" signal at the flasher relay only goes up to about 5.3V for the first two or three flashes, then drops to zero, even though the 49A signal is still good, and the outside lights are still flashing.

Gonna troubleshoot some more this weekend, but this problem is really getting on my nerves!

By the way, does anyone have a readable electrical diagram for a '74 non-automatic US model '02?

That would help a lot!